In the production of glass fibers, it is customary to pelletize the particulate glass batch employing an aqueous solution. The wet pellets are then predried and preheated in a hopper through which they move downwardly as a bed which contacts an upwardly moving mass of hot gases. These gases frequently are products of combustion from the furnace in which the pellets are subsequently melted. The preheated pellets are then introduced into the furnace in which they are melted to form molten glass from which glass fibers can be formed.
Certain difficulties are frequently encountered with such a process. One difficulty involves the tendency of the pellets to cake in the upper portion, or the drying section, of the hopper. A second difficulty involves particulate carry-over in the hot gas stream emitted from the hopper. The present invention is directed to the solution of these problems and has, as one of its objects, the attainment of those operating conditions particularly necessary to prevent pellet agglomeration, as set forth in U.S. application Ser. No. 095,870, now U.S. Pat. No. 4,248,615 to S. Seng et al., the disclosure of which is incorporated herein be reference.